Death of a horse infected experimentally with Anaplasma phagocytophilum

A 19-year-old horse that was one of a group of six horses infected experimentally with Anaplasma phagocytophilum for a study of the pathogenesis of equine granulocytic ehrlichiosis died suddenly two days after first showing clinical signs of disease. The clinical signs and laboratory findings observed before its death were similar to all those of the other infected horses, and to previous reports of this disease. A postmortem examination revealed widespread haemorrhaging in its internal organs, and vasculitis and thrombosis in the kidneys. These changes are consistent with disseminated intravascular coagulation, which has previously been reported in human beings infected with the presumably identical agent of human granulocytic ehrlichiosis.     

不同生长调节物质对丹参愈伤组织的诱导效应

以丹参(SalviamiltiorrhizaBunge)无菌苗的茎、叶为外植体,接种于附加2,4-D、NAA、6-BA及其组合的MS固体培养基上。结果表明:单独使用三种植物生长调节物质在一定浓度范围内均能产生愈伤组织;配合使用外源生长素和细胞分裂素,能获得出愈率高、生长快、质量好的愈伤组织;最佳组合的诱导培养基为MS 2,4-D2．0mg／L 6-BA1．0mg／L;2,4-D对丹参愈伤组织的诱导有促进作用;但当2,4-D的浓度在4mg／L以上时,对愈伤组织的生长有抑制作用。     

self-(in)compatibility almond genotypes: A review

To compile self-(in)compatibility almond genotypes, a review of 133 commercial cultivars of wide geographical origin was made. The information gathered from own and mainly published work will be useful for both grower's cultivar choice when planting and for breeder's cross design when planning. The almond S genotypes compiled were identified using five different methods: biological (pollination tests in the field and in the laboratory) and molecular (RNases, PCR and sequencing). In most cases, genotypes were assigned after combining more than one technique. Cultivars were classified into three categories: self-incompatible (99), self-compatible (16) and doubtful self-incompatible (18). The database is divided in 9 fields (name, origin, parentage, obtention year (crossing, selection or release), S genotype, technique used, reference, consensus genotype, and cross incompatibility group). A study of the 27 S alleles already identified and their geographical distribution within the cultivated almond is also presented. The study was divided into cultivars of known and unknown parentage and the distribution of S alleles frequencies was uneven among the 133 cultivars. S allele frequencies are related to geographical origin. Some alleles (S ₁, S ₅, S ₇ and S ₈) are more frequently observed than the others among cultivars of both known and unknown parentage. In the cultivated almond, the S f allele is only found in the Puglia region, Italy. The S _f frequency is three times higher in cultivars released from breeding programmes than in cultivars selected by growers. From the 351 resulting possible genotypes by combination of the 27 S alleles identified only 20 CIG (0-XIX) have been established, which represents a small fraction of the whole genetic diversity of this polymorphic gene in almond.     

Quantitative trait loci (QTL) affecting sugars, organic acids and other biochemical properties possibly contributing to flavor, identified in four advanced backcross populations of tomato

Although the Advanced Backcross strategy has proven very useful for QTL detection in tomato, it has been used mainly in identifying QTL for agronomic traits such as yield, color, etc. Tomato flavor is an important quality characteristic, yet it has been difficult to assess flavor or traits that affect it. In this study the AB-QTL strategy was applied to four advanced backcross populations to identify QTL for biochemical properties that may contribute to the flavor of processed tomatoes, such as sugars and organic acids. A total of 222 QTL were identified for 15 traits, including flavor as assessed by a taste panel. Correlations of certain biochemicals with flavor and possible methods of assessing and improving flavor are discussed. In particular, QTL with very significant effects associated with the ratio of sugars/glutamic acid, a trait highly correlated with improved flavor, have been identified as good targets for future work in improving the flavor of tomatoes. This revised version was published online in August 2006 with corrections to the Cover Date.     

Sunflower mutant containing high levels of palmitic acid in high oleic background

A new sunflower mutant, CAS-12, was obtained, which has both high palmitic (≈30%) and high oleic acid contents, and also a substantial amount of palmitoleic acid (≈7%). The mutant was selected after X-ray irradiation of dry seeds of the inbred line BSD-2-423, which had normal palmitic (≈3%) and high oleic (≈88%) acid levels. The increase of palmitic and palmitoleic acids occurred at the expense of the oleic acid content, which decreased to around 55% in respect to the original line. Linoleic acid content is always under 5%. Palmitic and palmitoleic acid levels were similar to those of the high palmitic mutant CAS-5 obtained in a previous programme from a low oleic line isogenic to BSD-2-423 using a similar mutagenic treatment. In that previous programme we also selected three high stearic acid mutants using chemical mutagenic treatment on the same sunflower line (RDF-1-532). We attempted to obtain mutants in other lines but were unsuccessful. The isolation of similar mutants in isogenic parental lines illustrates the importance of the genetic background in the development of specific mutants with an altered seed oil fatty acid composition. The oil of this mutant will increase the range of potential uses of sunflower oil. This revised version was published online in July 2006 with corrections to the Cover Date.     

Precision of genetic relationship estimates based on molecular markers

Genetic progress through selection is directly related to the amount of variability present in the population and the quality of genes contributed by the parents. Genetic relationships between lines were studied using DNA marker-based estimates of genetic similarity. A statistical methodology using the width of a confidence interval was developed to determine the number of probes to be surveyed and the precision in the estimation of genetic distance between pairs of cultivars. Precision was affected by type of genetic distance used, the number of cultivars, and amount of genetic diversity present in the studied group. The width of a (1-α)% confidence interval decreased as the number of RFLP fragments increased. Oat and wheat diversity studies were used to illustrate the methodology. This revised version was published online in July 2006 with corrections to the Cover Date.     

Assessment of genetic relatedness of the genera Ananas and Pseudananas confirmed by RAPD markers

Genetic relationships among 18 accessions, including 16 of Ananas and two of Pseudananas, were investigated using RAPD molecular markers. The procedure for DNA extraction was adapted from the method of Dellaporta et al. (1983) where an incubation in proteinase K and a purification step were included. From the total of 148 markers scored,132 (89.2%) were polymorphic. The similarity matrix was used for cluster analysis. The phenogram developed from the RAPD bands showed that for most of the cases, the accessions within a species grouped together. Nevertheless, a moderate infraspecific genetic variation was observed. For example, DNA data grouped all A. comosus accessions with a mean similarity coefficient of 0.85. Comparable results were obtained with all other species investigated. The highest genetic divergence was found withinA. lucidus where the mean similarity coefficient among accessions was0.75. A similar level of genetic polymorphism was observed among species,therefore, a definition about which species were involved in the constitution of A. comosus genotypes was not possible. These results agree with the breeders standpoint suggesting that all Ananas species belong to the primary gene pool of pineapple. This revised version was published online in July 2006 with corrections to the Cover Date.     

Genetic variation for tolerance or resistance to barley yellow dwarf virus in durum wheat

Summary One durum wheat line (Triticum durum), cv. 82PCD476, with useful BYDV tolerance or resistance, was singled out of 5 152 lines evaluated between 1979 and 1986. A few other lines such as cv. Boohai and cv. 12th IDSN 227, slightly inferior to cv. 82PCD476, also showed some value. With an hybrid of cv. 12th IDSN227 with the susceptible cv. 84PCY-S531, broad-sense heritability values of 0.37–0.41 were obtained for symptoms and a heritability value of 0.55 was obtained for the total weight of spikes. The weight of spikes was considered as a good indicator of wheat tolerance to BYDV. Although BYDV resistance or tolerance genes are not very common in durum wheat, sources of heritable resistance could be found. However, the resistance ofT. aestivum to BYDV was superior to the one found inT. durum.Cintribution no. 323